ESR 18:35-45 (2012)  -  DOI: https://doi.org/10.3354/esr00428

Population structure and dispersal patterns of loggerhead sea turtles Caretta caretta in Tunisian coastal waters, central Mediterranean

Olfa Chaieb1,2,*, Ali Elouaer2, Fulvio Maffucci3, Sami Karaa4, Mohamed Nejmeddine Bradai2, Hedia ElHili2, Flegra Bentivegna3, Khaled Said1, Noureddine Chatti

1Laboratory of Genetics, Biodiversity and Bio-resources Development -LR11ES41-, Higher Institute of Biotechnology  of Monastir, University of Monastir, 5000 Tunisia
2Laboratory of Marine Biodiversity and Biotechnology, National Institute of Sea Sciences and Technologies, Tunisia
3Stazione Zoologica ‘Anton Dohrn’, Villa Communale, Naples, Italy
4Faculty of Sciences, University of Sfax, Tunisia

ABSTRACT: Understanding the dispersal pattern and mechanisms affecting the mixing of Endangered loggerhead sea turtles Caretta caretta is a key issue for establishing sound conservation strategies. Loggerhead turtles are commonly encountered all along the Tunisian coast and particularly in the Gulf of Gabès, which is one of the most important foraging habitats for this species in the Mediterranean Sea. We conducted extensive sampling of 175 juvenile and adult loggerhead turtles that were stranded or incidentally captured in the areas along the northern (NTC), eastern (Gulf of Hammamet, GHAM) and southern (Gulf of Gabès, GGAB) Tunisian coast over a 6 yr period (2004 to 2009). A 380 bp fragment of the mitochondrial DNA control region was sequenced and analysed. Seven haplotypes were revealed, and a gradual variation in haplotype frequencies was observed among the studied areas. The extreme samples (NTC and GGAB) differed genetically from each other, while both were similar to the central sample (GHAM). This finding was confirmed by mixed stock analysis estimates, which suggested that the proportions of Atlantic turtles were very high in the NTC and decreased southward, while the proportions of Mediterranean contributions were higher in the GGAB and decreased in the opposite direction. The observed pattern of genetic variation and turtle distribution, which is probably related to differences in geomorphology and sea surface currents among these coastal areas, should be considered in future management plans.


KEY WORDS: Loggerhead sea turtle · Mitochondrial DNA · Foraging · Dispersal · Mixed stock analysis


Full text in pdf format 
Cite this article as: Chaieb O, Elouaer A, Maffucci F, Karaa S and others (2012) Population structure and dispersal patterns of loggerhead sea turtles Caretta caretta in Tunisian coastal waters, central Mediterranean. Endang Species Res 18:35-45. https://doi.org/10.3354/esr00428

Export citation
Mail this link - Contents Mailing Lists - RSS
- -